What (who) is orthogonal instruction set - definition
orthogonal instruction set
<architecture> An instruction set where all (or most)
instructions have the same format and all registers and
addressing modes can be used interchangeably - the choices
of op code, register, and addressing mode are mutually
independent (loosely speaking, the choices are
"orthogonal"). This contrasts with some early Intel
microprocessors where only certain registers could be used
by certain instructions.
Examples include the PDP-11, 680x0, ARM, VAX.
(2002-06-26)
Orthogonal instruction set
In computer engineering, an orthogonal instruction set is an instruction set architecture where all instruction types can use all addressing modes. It is "orthogonal" in the sense that the instruction type and the addressing mode vary independently.
Reduced Instruction Set Computer
![An IBM [[PowerPC 601]] RISC microprocessor](https://commons.wikimedia.org/wiki/Special:FilePath/IBM PowerPC601 PPC601FD-080-2 top.jpg?width=200 "An IBM [[PowerPC 601]] RISC microprocessor")
PROCESSOR EXECUTING ONE INSTRUCTION IN MINIMAL CLOCK CYCLES
Reduced Instruction Set Computer; RISC processor; Reduced Instruction Set Code; Reduced Instruction Set Computing; RISC; RISC-based; RISC-based system; RISC System/6000 SP; Reduced instruction set; RISC architectures; RISC instruction set; RISC-based computer design approach; RISC principles; Reduced instruction set computing
<processor> (RISC) A processor whose design is based on the
rapid execution of a sequence of simple instructions rather
than on the provision of a large variety of complex
instructions (as in a Complex Instruction Set Computer).
Features which are generally found in RISC designs are uniform
instruction encoding (e.g. the op-code is always in the same
bit positions in each instruction which is always one word
long), which allows faster decoding; a homogenous {register
set}, allowing any register to be used in any context and
simplifying compiler design; and simple addressing modes
with more complex modes replaced by sequences of simple
arithmetic instructions.
Examples of (more or less) RISC processors are the {Berkeley
RISC}, HP-PA, Clipper, i960, AMD 29000, MIPS R2000
and DEC Alpha. IBM's first RISC computer was the RT/PC
(IBM 801), they now produce the RISC-based {RISC
System/6000} and SP/2 lines.
Despite Apple Computer's bogus claims for their
PowerPC-based Macintoshes, the first RISC processor used
in a personal computer was the Advanced RISC Machine (ARM)
used in the Acorn Archimedes.
(1997-06-03)
Wikipedia
Orthogonal instruction set
In computer engineering, an orthogonal instruction set is an instruction set architecture where all instruction types can use all addressing modes. It is "orthogonal" in the sense that the instruction type and the addressing mode vary independently.
